Justification:
While there have been declines documented in some areas, these are not believed to have substantially affected the global population. In addition, it has a wide distribution, large population and no apparent major threats other than coral loss. It is listed as Least Concern.

This species is distributed from Christmas Island (Australia) in the eastern Indian Ocean through Indonesia, New Guinea (Indonesia and Papua New Guinea), and the Philippines east to Fiji. It ranges as far north as southern Japan, to northern New South Wales (Australia) and New Caledonia in the south (Pyle 2001, G.R. Allen pers. comm. 2006). It is found between 1-20 m in depth. Range size ~31.7 million km2, from values estimated by Jones et al. (2002) based on projection of distribution maps from Allen et al. (1998).

It has declined significantly on the Great Barrier Reef (Pratchett et al. 2006), where there has been coral loss and bleaching. However, in the Pacific bleaching has been patchy, and it is unclear to what extent this affects the global population.

In some areas it can be a very common species: in the northern Great Barrier Reef the estimated mean is 1.67 individuals per 200 m2 (Pratchett and Berumen 2008).

This species is found within the clear waters of fringing reefs (Allen 1980). It is a territorial species and actively chases away other butterflyfishes encroaching on its food supply (Allen 1980, G.R. Allen pers. comm. 2006). Mostly occurs in pairs. It is an obligate corallivore and feeds predominantly on Acropora corals (e.g., Pratchett 2005), but it also occurs in habitats with no Acropora corals.

Relies on live coral for food and recruitment, and has declined significantly following climate-induced coral depletion on the Great Barrier Reef (Pratchett et al. 2006). However coral bleaching and coral loss has been patchy throughout the Pacific Ocean, and localized declines due to coral loss have not substantially affected the global population. There do not appear to be any major threats other than coral loss.